Data Coverage

        my $input = int shift;
        my @squares = (0, 1, 5, 9);
        if ($input < 4 && $input > -4)
        {
            print $squares[abs $input];
        }

• Full coverage with input of -4, 0 and 4

• What's two squared?

• Check each value is read

• Lookup table and tests get values from same source